A Florida teenager who, along with his grandmother, had been reported missing earlier in the week has been detained at the United States border with Canada.

Logan Mott, 15, was reported missing after he and his grandmother Kristina French, 53, were supposed to pick up his father and his father's girlfriend from a Jacksonville area airport, CBS News reports. He was detained late Friday.

The body of an individual believed to be French was discovered in a shallow grave in the backyard of Mott's father, who is her son, on Friday.

Logan Mott, 15, was detained at the US-Canada border late on Friday. He and his grandmother Kristina French, 53, were reported missing in Florida earlier this week

Police issued an arrest warrant for Mott earlier on Friday on charges of auto theft. French's Dodge Dart was missing from her home in the Jacksonville area. Guns were also missing from the home of Mott's father, who is French's son